Golgi

Functions-

  • modifies, sorts, and packages macromolecules necessary for life for cell secretion
  • primarily modifies proteins from rough ER
  • creation of lysosomes
external image golgifigure1.jpg

Step-by-Step:

1. Proteins and lipids built in the smooth and rough ER move through the cytoplasm in tiny bubble-like vesicles until they reach the Golgi complex.
2. Vesicles fuse with the Golgi membranes and release their internally stored molecules into the organelle.
3. Compounds are further processed by the Golgi apparatus, which adds molecules or chops tiny pieces off the ends.
4. Product is extruded from the GA in a vesicle and directed to its final destination inside or outside the cell.

  • secretions of proteins or glycoproteins OR
  • returned to the endoplasmic reticulum
external image gol2.jpg
OR
  • undergo maturation to become lysosomes

external image rer9.jpg
3 Different Paths:
  • exocytotic vesicles
  • secretory vesicles
  • lysosomal vesicles


Current Research:

Protein Sorting in Eukaryotic Cells
Led by: David Domingo Sabatini Ph.D., Doc. en Med. (Frederick L. Ehrman Professor of Cell Biology and Chairman)
Research Summary: sorting processes that occur in the trans region of the Golgi apparatus, and select different subsets of proteins for incorporation into vesicles that deliver them to developing secretory granules, lysosomes, or the different domains of the plasma membrane of polarized epithelial cells.
Organisms: Eurkaryotic cells
Institution: New York University

Golgi apparatus, centrosome, cell cycle regulation, Chlamydia, pathogenesis
Led by: Christine Suetterlin (Assistant Professor, Developmental & Cell Biology School of Biological Sciences)
Research Summary: focuses on determining the mechanism by which Golgi proteins regulate the centrosome during the cell cycle
  • how the peripheral Golgi proteins, GM130 and GRASP65, control the organization and function of the centrosome during interphase and mitosis
  • understanding the molecular mechanism by which Chlamydia reroutes host trafficking pathways to obtain host derived proteins and lipids
Organisms: mammals
Institution: University of California at Irvine


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BIBLIOGRAPHY

Campbell, Neil A. Biology. 8th ed. San Francisco: Pearson Education, Inc., 2008.
Childs, Gwen V., Ph.D. "Golgi Complex: Structure and Function." The Golgi Complex. 5 Dec. 2003. University Of Texas Medical Branch. 9 Oct. 2008 <http://cellbio.utmb.edu/cellbio/GOLGI.HTM>.
Davidson, Michael W. "The Golgi Apparatus." Molecular Expressions. 13 Nov. 2004. Florida State University. 9 Oct. 2008 <http://micro.magnet.fsu.edu/cells/ golgi/golgiapparatus.html>.
"Golgi Apparatus." Wikipedia, The Free Encyclopedia. 8 Oct. 2008. 9 Oct. 2008
<http://en.wikipedia.org/wiki/Golgi_apparatus>.
Ross, John. Golgi Apparatus. 17 Aug. 2004. 9 Oct. 2008
<http://www.jdaross.cwc.net/golgi.htm>.
Sabatini, David Domingo, Ph.D., Doc. en Med. "David Domingo Sabatini Ph.D., Doc.
en Med." NYU Langone Medical Center. 2008. 9 Oct. 2008
<http://www.med.nyu.edu/research/sabatd01.html>.
Suetterlin, Christine, Ph.D. "Christine Suetterlin." UC Irvine - Faculty Profile
System. 14 May 2007. The Regents of the University of California. 9
Oct. 2008 <http://www.faculty.uci.edu/profile.cfm?faculty_id=5237>.




Golgi
by Logan Pulido

Structure
  • Found in both plant and animal cells (eukaryote)
  • Compromised of a series of 5-8 membrane covered sacs called cisternae
  • Usually located near cell nucleus
  • Relatively large size
[[image:file:C:%5CDOCUME%7E1%5CPATRIC%7E1%5CLOCALS%7E1%5CTemp%5Cmsohtml1%5C03%5Cclip_image001.jpg width="373" height="288"]][[image:file:C:%5CDOCUME%7E1%5CPATRIC%7E1%5CLOCALS%7E1%5CTemp%5Cmsohtml1%5C03%5Cclip_image001.jpg width="373" height="288"]][[image:file:C:%5CDOCUME%7E1%5CPATRIC%7E1%5CLOCALS%7E1%5CTemp%5Cmsohtml1%5C03%5Cclip_image001.jpg width="373" height="288"]]
[[image:file:C:%5CDOCUME%7E1%5CPATRIC%7E1%5CLOCALS%7E1%5CTemp%5Cmsohtml1%5C03%5Cclip_image001.jpg width="373" height="288"]]external image golgifigure1.jpg

  • The cis face is the end of the organelle where substances enter from the ER for processing and it is located near the ER of a cell
The lumen is the inner open space of cisternae that contains enzymes
· The trans face is where the processed compounds exit in the form of small detached vesicles and is located near the plasma membrane

Function
  • Process, modify, sort, and package macromolecules such as proteins and lipids, that are required for life, for cell secretion or for use within a cell
  • Primarily modify proteins and lipids delivered from rough ER
  • Creates lysosomes
  • It modifies proteins and lipids that have been built in the ER and prepares them for export outside of the cell or for transport to other locations in the cell

Process

external image rer9.jpg


  • Smooth and rough ER build proteins, carbohydrates, phospholipids, and other molecules that bud off in tiny bubble-like vesicles that move through the cytoplasm until they reach the Golgi complex
  • The cis face of the Golgi membranes and the vesicles fuse, releasing the internally stored molecules into the organelle

  • The Golgi apparatus then processes the compounds, adding or subtracting off tiny pieces. Enzymes found in the lumen modify the compound by adding or subtracting individual sugar monomers, phosphate groups…
  • After the modification process in complete, the product is then extruded from the trans face of the Golgi apparatus in a vesicle and directed to its final destination outside or inside the cell. (the products are secretions of proteins, are returned to the ER, or may undergo maturation into lysosomes)
  • Three different pathways (1. exocytotic vesicles-process by which a cell directs secretory vesicles out of the cell membrane. 2. secretory vesicles-hormones, neurotransmitters - are packaged in secretory vesicles at the Golgi apparatus. The secretory vesicles are then transported to the cell surface for release. 3. lysosomal vesicles- )

Current Research

Yale Scientists Give The Golgi Apparatus Its Own Identity, Paving The Way For More Targeted Cancer Research

Led by: Warren’s research team included Joachim Seemann and Marc Pypaert at Yale and Eija Jokitalo from the Institute of Biotechnology in Helsinki, Finland.

Research Summary: the Golgi apparatus is an organelle that exists independently of the larger endoplasmic reticulum and is a crucial component of cell division.
· Researchers once thought that the Golgi apparatus was no more than an outgrowth of an organelle called the endoplasmic reticulum. Now they show that it is an organelle within a cell that has its own autonomy and so must grow and divide to keep pace with the growth and division of the cell it inhabits.
· The Golgi apparatus is normally thought of as a stack of membrane compartments through which the secretory proteins pass, but Warren and colleagues have been able to show that the Golgi has an existence even when these membranes are removed from the apparatus. "We found that there are proteins, which we term matrix proteins, that form a scaffold to organize the membranes," said Warren. "We think this scaffold might be the Golgi apparatus proper, responsible for its growth, division.
· The discovery gives researchers a better understanding of the cell division process and of the processes present in the uncontrolled cell division that marks cancer.

Organisms: mammals
Institution: Yale University


Bibliography

Campbell, Neil A. Biology. 8th ed. San Francisco: Pearson Education, Inc., 2008.
Childs, Gwen V., Ph.D. "Golgi Complex: Structure and Function." The Golgi Complex. 5 Dec. 2003. University Of Texas Medical Branch. 9 Oct. 2008 <http://cellbio.utmb.edu/cellbio/GOLGI.HTM>.
Golgi Apparatus." Wikipedia, The Free Encyclopedia. 8 Oct. 2008. 9 Oct. 2008
<http://en.wikipedia.org/wiki/Golgi_apparatus>.
Suetterlin, Christine, Ph.D. "Christine Suetterlin." UC Irvine - Faculty Profile
System. 14 May 2007. The Regents of the University of California. 9
Oct. 2008 <http://www.faculty.uci.edu/profile.cfm?faculty_id=5237>.
Yale University. "Yale Scientists Give The Golgi Apparatus Its Own Identity, Paving The Way For More Targeted Cancer Research." ScienceDaily 22 November 2000. 13 October 2008 <http://www.sciencedaily.com­ /releases/2000/11/001120074801.htm>.